Nullability cleanup (2023-11-26)

Author: AndreyAkinshin

src/BenchmarkDotNet/Analysers/BaselineCustomAnalyzer.cs

@@ -25,7 +25,7 @@ protected override IEnumerable<Conclusion> AnalyseSummary(Summary summary)
 
             foreach (var benchmarkCase in summary.BenchmarksCases)
             {
-                string logicalGroupKey = summary.GetLogicalGroupKey(benchmarkCase);
+                string? logicalGroupKey = summary.GetLogicalGroupKey(benchmarkCase);
                 var baseline = summary.GetBaseline(logicalGroupKey);
                 if (BaselineCustomColumn.ResultsAreInvalid(summary, benchmarkCase, baseline) == false)
                     continue;

src/BenchmarkDotNet/Analysers/OutliersAnalyser.cs

@@ -53,7 +53,7 @@ string Format(int n, string verb)
                 return $"{n} {words} {verb}";
             }
 
-            var rangeMessages = new List<string> { GetRangeMessage(lowerOutliers, cultureInfo), GetRangeMessage(upperOutliers, cultureInfo) };
+            var rangeMessages = new List<string?> { GetRangeMessage(lowerOutliers, cultureInfo), GetRangeMessage(upperOutliers, cultureInfo) };
             rangeMessages.RemoveAll(string.IsNullOrEmpty);
             string rangeMessage = rangeMessages.Any()
                 ? " (" + string.Join(", ", rangeMessages) + ")"

src/BenchmarkDotNet/Columns/BaselineCustomColumn.cs

@@ -43,7 +43,7 @@ public abstract string GetValue(Summary summary, BenchmarkCase benchmarkCase, St
         public override string ToString() => ColumnName;
         public bool IsDefault(Summary summary, BenchmarkCase benchmarkCase) => false;
 
-        internal static bool ResultsAreInvalid(Summary summary, BenchmarkCase benchmarkCase, BenchmarkCase baseline)
+        internal static bool ResultsAreInvalid(Summary summary, BenchmarkCase benchmarkCase, BenchmarkCase? baseline)
         {
             return baseline == null ||
                    summary[baseline] == null ||

src/BenchmarkDotNet/Columns/TagColumn.cs

@@ -19,7 +19,7 @@ public TagColumn(string columnName, Func<string, string> getTag)
         }
 
         public bool IsDefault(Summary summary, BenchmarkCase benchmarkCase) => false;
-        public string GetValue(Summary summary, BenchmarkCase benchmarkCase) => getTag(benchmarkCase.Descriptor.WorkloadMethod.Name);
+        public string GetValue(Summary summary, BenchmarkCase benchmarkCase) => getTag(benchmarkCase.Descriptor?.WorkloadMethod?.Name ?? "");
 
         public bool IsAvailable(Summary summary) => true;
         public bool AlwaysShow => true;

src/BenchmarkDotNet/Configs/ImmutableConfig.cs

@@ -119,7 +119,7 @@ internal ImmutableConfig(
 
         public bool HasExtraStatsDiagnoser() => HasMemoryDiagnoser() || HasThreadingDiagnoser() || HasExceptionDiagnoser();
 
-        public IDiagnoser GetCompositeDiagnoser(BenchmarkCase benchmarkCase, RunMode runMode)
+        public IDiagnoser? GetCompositeDiagnoser(BenchmarkCase benchmarkCase, RunMode runMode)
         {
             var diagnosersForGivenMode = diagnosers.Where(diagnoser => diagnoser.GetRunMode(benchmarkCase) == runMode).ToImmutableHashSet();
 

src/BenchmarkDotNet/Diagnosers/DiagnoserActionParameters.cs

@@ -6,7 +6,7 @@ namespace BenchmarkDotNet.Diagnosers
 {
     public class DiagnoserActionParameters
     {
-        public DiagnoserActionParameters(Process process, BenchmarkCase benchmarkCase, BenchmarkId benchmarkId)
+        public DiagnoserActionParameters(Process? process, BenchmarkCase benchmarkCase, BenchmarkId benchmarkId)
         {
             Process = process;
             BenchmarkCase = benchmarkCase;

src/BenchmarkDotNet/Exporters/Json/SimpleJson.cs

@@ -1,3 +1,4 @@
+#nullable disable
 // ReSharper disable All
 //-----------------------------------------------------------------------
 // <copyright file="SimpleJson.cs" company="The Outercurve Foundation">

src/BenchmarkDotNet/Extensions/CommonExtensions.cs

@@ -32,18 +32,20 @@ public static string GetColumnTitle(this IColumn column, SummaryStyle style)
             }
         }
 
-        public static bool IsNullOrEmpty<T>(this IReadOnlyCollection<T> value) => value == null || value.Count == 0;
+        public static bool IsNullOrEmpty<T>(this IReadOnlyCollection<T>? value) => value == null || value.Count == 0;
         public static bool IsEmpty<T>(this IReadOnlyCollection<T> value) => value.Count == 0;
         public static bool IsEmpty<T>(this IEnumerable<T> value) => !value.Any();
 
+        public static IEnumerable<T> WhereNotNull<T>(this IEnumerable<T?> values) => values.Where(value => value != null).Cast<T>();
+
         public static void AddRange<T>(this HashSet<T> hashSet, IEnumerable<T> collection)
         {
             foreach (var item in collection)
                 hashSet.Add(item);
         }
 
 #if NETSTANDARD2_0
-        public static TValue GetValueOrDefault<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key)
+        public static TValue? GetValueOrDefault<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key)
             => dictionary.TryGetValue(key, out var value) ? value : default;
 #endif
 
@@ -97,15 +99,17 @@ internal static string DeleteFileIfExists(this string filePath)
 
         internal static string EnsureFolderExists(this string filePath)
         {
-            string directoryPath = Path.GetDirectoryName(filePath);
+            string? directoryPath = Path.GetDirectoryName(filePath);
+            if (directoryPath == null)
+                throw new ArgumentException($"Can't get directory path from '{filePath}'");
 
             if (!Directory.Exists(directoryPath))
                 Directory.CreateDirectory(directoryPath);
 
             return filePath;
         }
 
-        internal static bool IsNotNullButDoesNotExist(this FileSystemInfo fileInfo)
+        internal static bool IsNotNullButDoesNotExist(this FileSystemInfo? fileInfo)
             => fileInfo != null && !fileInfo.Exists;
     }
 }

src/BenchmarkDotNet/Helpers/Assertion.cs

@@ -0,0 +1,14 @@
+using System;
+using JetBrains.Annotations;
+
+namespace BenchmarkDotNet.Helpers;
+
+internal static class Assertion
+{
+    [AssertionMethod]
+    public static void NotNull(string name, object? value)
+    {
+        if (value == null)
+            throw new ArgumentNullException(name, $"{name} can't be null");
+    }
+}

src/BenchmarkDotNet/Helpers/DirtyAssemblyResolveHelper.cs

@@ -28,7 +28,7 @@ internal class DirtyAssemblyResolveHelper : IDisposable
     /// "the handler is invoked whenever the runtime fails to bind to an assembly by name."
     /// </summary>
     /// <returns>not null when we find it manually, null when can't help</returns>
-    private Assembly HelpTheFrameworkToResolveTheAssembly(object sender, ResolveEventArgs args)
+    private Assembly? HelpTheFrameworkToResolveTheAssembly(object sender, ResolveEventArgs args)
     {
         var fullName = new AssemblyName(args.Name);
         string simpleName = fullName.Name;